多目涡虫咽部焰细胞的超微结构

用电子显微镜研究了多目涡虫(Polycelis wutaishanica Liu,sp.nov.)咽壁内焰细胞的超微结构,结果表明:涡虫咽壁长柱状肌细胞间存在很多焰细胞;焰细胞横切可以看到两种形态结构:一种是焰细胞形成一个空腔,内含很多纤毛;另一种焰细胞形成两个偶连的空腔,内含纤毛,两个偶连的空腔通过孔窗相连,在孔窗上可见微绒毛.细胞外围伸出很多很长的突起,在肌细胞间延伸;焰细胞内存在与胞外基质和腔相通的狭长毛细管,管的起始部膨大,内有微绒毛,末端开口于焰细胞围成的腔内.因此,可以确定焰细胞有一个很大的表面积,焰细胞的结构特点反映了其除了过滤和排泄功能之外,可能还有吸收和细胞内消化的功能.

Ultrastructure of the Protonephridial Flame Cell of the Freshwater Planarian Polycelis Wutaishanica

The protonephridial flame cell in the pharynx wall of the freshwater planarian Polycelis wutaishanica Liu is studied by electron microscopy.The results indicate that there are many flame cells among long columnar muscle fibers in the pharynx wall.Two sorts of configuration are seen with transverse section of the flame cell.One is that the flame cell form a cavum with luminal cilia,the other is that the flame cell form twin cava with luminal cilia.Twin cava communicate with eatch other by fenestrae with microvilli.The periphery of the flame cell protrudes a lot of long processes that extend among muscle fibers.There are capillaries in the flame cell that connect extracellular ground substance to the cavum.The inceptive part of the capillary expands with a few microvilli.The end of the capillary connects to the cavum.Hence,the flame cell has a very large surface.In general,the planarian flame cell seems to function not only in the filtration of body fluid and excretion but also in the absorption and intracellular digestion of substances.